(() => {
    // 函数的参数名不需要与接口里定义的名字相匹配
    let mySearch;
    mySearch = function (source, subString) {
        let result = source.search(subString);
        return result > -1;
    };
    console.log(mySearch('我变帅了', '帅'));
    console.log(mySearch('我变帅了', '丑'));
})();
